The Gannett Wisconsin Media Investigative Team (http://post.cr/1cqAGrv ) reported on the documents Tuesday, saying they show the grand jury has subpoenaed documents related to Butler. Gannett Wisconsin Media earlier reported the IRS has been looking into a charity run by Butler.

Federal court filings do not list any charges against Butler, and he told Gannett Wisconsin Media on Monday he was unaware of the investigation.

"We are fully complying with all requirements relating to our foundation and have outside experts engaged," Butler said in an email. "I have not been contacted in any way by a regulatory body. Of course any such contact would be handled in the normal business course."

Assistant U.S. Attorney Munish Sharda, who signed the subpoenas, declined to comment or confirm the investigation to Gannett Wisconsin Media. Myra Longfield, spokeswoman for the U.S. Attorney's Office in Wisconsin's Western District, said investigations are not made public until any potential charges are filed.

Butler did not immediately respond to an email from The Associated Press Tuesday. A home phone number for Butler could not be found.

The LeRoy Butler Foundation hasn't filed with the IRS since 2002, even though Butler continued raising money under that name through this year, Gannett Wisconsin Media reported earlier.

Butler, 45, was a four-time All-Pro and played for the Packers from 1990 to 2001.